docs: def pagebreak(type='page', orient='portrait'):
      '''Insert a break, default 'page'.
      See http://openxmldeveloper.org/forums/thread/4075.aspx
      Return our page break element.'''
      # Need to enumerate different types of page breaks.
      validtypes = ['page', 'section']
      if type not in validtypes:
          tmpl = 'Page break style "%s" not implemented. Valid styles: %s.'
          raise ValueError(tmpl % (type, validtypes))
      pagebreak = makeelement('p')
      if type == 'page':
          run = makeelement('r')
          br = makeelement('br', attributes={'type': type})
          run.append(br)
          pagebreak.append(run)
      elif type == 'section':
          pPr = makeelement('pPr')
          sectPr = makeelement('sectPr')
          if orient == 'portrait':
              pgSz = makeelement('pgSz', attributes={'w': '12240', 'h': '15840'})
          elif orient == 'landscape':
              pgSz = makeelement('pgSz', attributes={'h': '12240', 'w': '15840',
                                                     'orient': 'landscape'})
          sectPr.append(pgSz)
          pPr.append(sectPr)
          pagebreak.append(pPr)
      return pagebreak